Tuesday, April 25, 2017

Okeanos Follow-up: Giant Sea-Spiders EAT! Cnidarians, Anemones, Hydroids & Corals! oh my!

Many of you know that I occasionally "call in" when the NOAA deep-sea research platform Okeanos Explorer goes out to see on its missions. (remember the next leg BEGINS APRIL 27  http://oceanexplorer.noaa.gov/okeanos/media/exstream/exstream.html)

Mostly I call in on starfishes or echinoderm biology..but I do have a broad interest in deep-sea biology. And I just LOVE seeing observations like the one above: a weird animal doing something no one is familiar with!

And the BEST thing about Okeanos Explorer? EVERYONE can enjoy it along with you!! Here's a BUNCH of Sea spider observations from the Atlantic Okeanos Explorer in 2014! 

...BUT of course, our ship and shore-side scientists can't know EVERYTHING. We'll often observe an event, many of us make note of it in case we see it again and often times we'll move on.... forgetting about it until such a time when the observation comes up again.

ONE such observation was one from 2014 on the Atlantic Physalia Seamount wherein we observed a sea spider in the genus Colossendeis sp. with its proboscis (that's the long cigar shaped feeding tube) stuckINTO into this hydroid (an animal similar to a Hydra from freshwater)! Was this feeding? Was it NEW?
Physalia Seamount in the North Atlantic
A brief into: Sea spiders are not spiders. They belong to a group known as the Pycnogonids (also called the pantopods) which are mysterious arthropods. Some folks consider them distantly related to the greater group of arachnids whereas others think they are even more unusual...

Most sea spiders are pretty tiny and are less than about an inch (2 cm) across and its not unusual for them to be quite cryptic. So even though they can be present, you really DO have to look for them...
Here a photoessay of tropical, shallow water species by scientist/photographer Arthur Anker displaying some spectactular colors!   Here's a spectacular male carrying eggs..
Male ovigerous sea spider (Pycnogonida)

Many live in shallow water but are never seen (hidden and small)... but that's NOT a problem with the deep-sea and Antarctic species!  There's one frequently encountered genus: Colossendeis which is one of the largest known sea spiders reaching a leg-to-leg diameter of over 50 cm! that's almost a FOOT and a HALF!

Most members of Colossendeis live in the proper deep ocean abyss: roughly 1000 to 5000 m and also in Antarctica where the cold-waters allow them to occur in relatively shallow water settings.

Note also the sizeable cigar shaped projection at the top end! That's called the PROBOSCIS! That will be important later! That is presumably what they use to feed.
Image from page 96 of "A contribution to American thalassography; three cruises of the United States Coast and geodetic survey steamer "Blake," in the Gulf of Mexico, in the Caribbean Sea, and along the Atlantic coast of the United States, from 1877 to 18
Unfortunately, there is relatively little information known about sea spiders..... And the deep-sea species? Even less!

So, were the observations something unusual? Has science encountered something like that before??

But much to my delight: YES! There WAS a previous account of sea spiders feeding! and WOO HOO!  It turns out my friends at the Monterey Bay Aquarium Research Institute in Moss Landing, California actually observed something JUST LIKE THIS in 2010!!! Here was their blog post about it! 


The paper, by Caren Braby, Vicky Pearse, Bonnie Bain and Bob Vrijenhoek was published in Invertebrate Biology in 2009, 128(4): 359-363. and it documented "Pycnogonid-cnidarian trophic interaction in the deep Monterey Submarine Canyon"

They observed the same genus, Colossendeis, but at least two species, C. gigas and C. japonica feeding on commonly encountered sea anemones in the deeps of Monterey Canyon.
Braby's paper reveals that only Colossendeis in Antarctica had been observed feeding. These animals fed on limpets and bristle worms and in 1999 sea spiders were observed feeding on sea anemones

Braby et al.'s observations were the first for deep-sea Colossendeis (as opposed to Antarctic) species. Her team's work focused on their feeding on the deep-sea "pom pom anemone" Liponema brevicornis, an unusual sea anemone which literally "rolls" along the bottom of the deep-sea in a manner similar to a tumbleweed!

After the last 2017 Okeanos leg in the Phoenix Islands, I rounded up a BUNCH of the sea spider-feeding observations and decided to share them here as a comparison! Who knows? perhaps it will inspire a further paper!

Remember that NOAA's Okeanos Explorer program has captured these images and made them available for EVERYONE's enjoyment! Please remember that the next time someone talks about government funded science!

Pacific Observations! Over the last few weeks of the Phoenix Island expedition, we saw a BOUNTY of sea spider feeding observations!  

Winslow Reef: This one had its proboscis firmly ensconced into this flytrap anemone and was apparently sucking something out of it! The rather lethargic looking appearance is likely the result of being on the receiving end of whatever is going on here...

And ANOTHER on Winslow Reef! that was QUITE a dive! Here's another flytrap anemone with a sea spider attacking it!   As we saw earlier from Monterey Canyon, sea anemones and other cnidarians seem to be one kind of preferred food!

Baker Island we saw one attacking what was identified as a cup coral...The proboscis seemed to be "drinking" pretty heavily on this one...


Howland Island.....and just for good measure they saw this one crawling over a glass sponge

More Atlantic Feeding? Here we had a sea spider in the Atlantic Nygren Canyon which has been identified as Pallenopsis (thanks to Bonnie Bain), climbing and possibly feeding on this sea pen.

So, unfortunately I'm not really a sea spider taxonomist, so beyond the genus Colossendeis, I'm not sure how many species we are looking at here..but images such as this inspire many questions: Is predation specific to species? Or generalized?  How significant are these events to the ecosystem?
Do sea spiders attack the big colonial corals as well?

Stay tuned for the next exciting episode!

Friday, March 17, 2017

Okeanos Tropical Pacific Highlights: RARE and BRILLIANT Echinoderms!!

Over the last 10 days or so since Okeanos Explorer has resumed its ROV-telepresence based exploration of the Phoenix Islands and adjacent areas in the tropical Pacific they've seen some REMARKABLE animals of all kinds, from corals to siphonophores, crabs to ribbon worms, etc... but particularly ECHINODERMS!

Before I get into the cool pix.. remember NOAA OPERATES Okeanos Explorer!! NOAA has been threatened with severe budget cuts. CONTACT YOUR CONGRESSIONAL REP AND TELL THEM THAT NOAA IS AN ESSENTIAL Agency!

1. PELAGOTHURIA!  The "TRUE" swimming Echinoderm!!
I have written about this amazing animal before when I found an image of it misidentified as a jellyfish in the Galapagos Rift 2011 Okeanos photo gallery and have written at some length about swimming sea cucumbers here.

Basically, almost all sea cucumbers and indeed most echinoderms are benthic..that is they live entirely on the sea floor and never get into the water column the way fish or jellyfish do.. Yes. Some sea cucumbers can swim but ultimately they return to the bottom.

Pelagothuria is unique because it LIVES SWIMMING in the water column! Similar to the way a jellyfish does. As a result of its strange lifestyle, it has MANY bizarre adaptations and looks unlike most other sea cucumbers much less other echinoderms!

Its not a commonly encountered animal..and we live in a wonderous time that we can see several minutes of HD video of this seldom seen animal swimming by...

The video for this can be found HERE:  http://oceanexplorer.noaa.gov/okeanos/explorations/ex1703/dailyupdates/media/video/dive08_seacuke/seacuke.html
Here are the feeding arms extended into the water...


Pelagothuria is contrasted with this other swimming sea cucumber which, after landing on the bottom, poops and then takes off! (from that unnamed seamount off Winslow Reef)



2. The strange irregular urchin Phrissocystis! From Polo Seamount, about 2100 m we saw one of the most seldom seen spatangoid urchins known! These are highly evolutionarily derived sea urchins which live by digging through and swallowing sediment looking for food.

Although they are bristling with spines, they are actually quite delicate. One collected many years ago apparently collapsed as soon as it was brought out of the water in the submersible collection box!

3. A stunning new phyrocrinid stalked crinoid! From an unamed seamount in the Phoenix Island chain, this bold and striking stalked crinoid was observed..and ultimately collected after it was identified as a new species by crinoid scientist Chuck Messing (based on a paper by Tunniclife et al.)

It was quite large with an unusual texture to the stalk and the cup...

4. The "jumping" brittle star Ophioplinthaca
Brittle stars, distant cousins of sea stars, are EVERYWHERE in the ocean. And especially in the deep-sea you can see them inhabiting numerous cracks, crevices and living on corals!

Some are VERY spiny.. such as this species, what I think is called Ophioplinthaca. We've been seeing these ever since the first leg of the Samoa Expedition.  They seem to occur on corals with the tissue removed.. possibly by the ophiuroid itself..

Another curiosity is that these seem to "jump" off their perches as soon as the ROV approaches. Whether this is due to light, vibration, the bow wave of the D2 or disturbance in the "ophiuroid force" (NOTE: Ophiuroid force does not exist) is unclear...



5. The enigmatic sea star Tremaster mirabilis Here's another strange one! A sea star that basically looks like a bowl on the top of a table!

We've seen these before on Atlantic Okeanos dives (see that here) and I wrote about this animal many years ago before people started seeing them alive..

There is nominally ONE species present in almost every ocean in the world.. they've been found in the Atlantic, around New Caledonia, near Hawaii and in the Antarctic. Not sure if they've been found in the Indian Ocean.

Interestingly, these were found in astonishing abundance on one of the seamount dives



5a. The Deep-Sea Slime Star HYMENASTER 
From Titov Seamount was this glorious, glorious deep-sea SLIME STAR, in the genus Hymenaster.

I've written about the shallow water representatives of this genus here. and explored the diversity of Hymenaster in the deep-sea here


*EXTRA! and of course a bunch of weird sea cucumbers!!
A deimatid sea cucumber with many tentacular extensions, this one from Swains Atoll
and this one from Titov Seamount  but they look to be similar if not identical


This one has been seen repeatedly rearing back and presenting what I think is its mouth into the water. so maybe feeding?

A red one from Polo Seamount
This interesting purple/translucent one from Polo Seamount

Some kind of translucent "sea pig" (family Elpidiidae?) also from Polo Seamount

Monday, March 6, 2017

Highlights from the recent NOAA Okeanos Explorer Samoa Expedition!

So, here is a nice highlight of various wonderful invertebrates observed by NOAA's deep-sea research vessel, the Okeanos Explorer which for all of 2016 and 2017 will be studying the massive marine reserves of American territory in the tropical Pacific!

DON'T FORGET OKEANOS LIVE FEED RESUMES MARCH 7!


But obviously, not everyone can watch EVERY day during the entire dive. So I present some cool highlights (but invertebrates) from the last leg of the research dive.  

My thanks to Santiago Herrera and Matthew Jackson the biology & geology science leads for this last epxpedition!!

If you have missed it and are interested you can always go to Twitter and search for #Okeanos often with #Samoa or other similar terms.


Also a reminder based on recent news about significant budget cuts to NOAA Remember that NOAA operates the Okeanos Explorer program!!  The oceans represent a HUGE unknown quantity and yet, we have no exploration arm to explore the amazing deeps of the Earth. Deep-sea News has made a GREAT argument about why we need an "Ocean NASA"! And right now, the closest thing NOAA gives us the closest thing to that! 

So, if you enjoy these and other images as well as the livestream RESEARCH and DISCOVERY please contact your congressional representative and LET THEM KNOW: DO NOT DEFUND NOAA.

and now.. onto some cool beasts!!


PROTISTS! 
Most of what I'll present here are animals, but in the deep regions of the ocean, single-celled organisms that are basically HUGE amoebas can develop fairly LARGE structures out of sediment. I've written about them here. Some are called xenophyophores but it turns out that there's a fair diversity of them.

Here's at least one structure observed on Utu Seamount at about 3030 meters! 


SPONGES!! Some of the most commonly encountered animals on these Okeanos dives are sponges. Sponges are relatively simple animals that are basically big masses of cells but some of them use specific kinds of materials to create skeletons.  Some use calcium carbonate, some use a fiber called spongin..and one group which is seen commonly in the deep-sea: glass or silicon dioxide.


Here's a large one with a thick stalk and a large opening on the "head"
This is a cool one: this is a cladorhizid sponge. Many cladorhizid sponges are predatory and I think this one is as well..

those spines emerging off the edge makes it a deadly deep-sea umbrella!
Here's another one from a different angel from Rose Atoll, about 2525 meters! 

This is a glass sponge in the Euplectellidae, which is often identifiable by the unusual "cap" on the top of the sponge.. These are known for having 2 commensal male and female mated shrimps which do not escape from the internal cavity.. 
I missed the name/identification on this one..but I like to point out that those brown "roots" are actually GLASS. Glass sponges often seem to be growing "living" fiber optic cable and have been studied for their optical properties! 

WEIRD CNIDARIANS!!
Cnidarians are of course-those animals with stinging cells and radial symmetry. Jellyfish, sea anemones, hydras, hydroids and so on.They account for a huge diversity in deep-sea habitats! 

This "cosmic jellyfish" has been making the rounds. Its been identified as Benthocodon hyalinus by my colleague Allen Collins at NMFS. It was observed on Utu Seamount at about 3006 meters!! 



Its not unusual for us to see a giant hydroid on these dives.. This one identified tentatively as Corymopha


One of the most noteworthy of the cnidarians observed was this Dandelion or benthic siphonophore. Siphonophores are colonial animals which are mostly found swimming though the ocean in long chains which in some instances can be meters long!  Familiar species include the painful Portuguese Man o War. 

BUT the species in this group live attached to the bottom, apparently with a huge array of feeding tentacles extended.. there's a blog about these waiting to be written! hopefully soon...
Similar in lifestyle-check out this tiny bottom living (aka benthic) ctenophore (or comb jelly). I've discussed these at length before here. Again, most comb jellies swim-but then you get these oddballs that have an active bottom life using their long tentacles to capture prey.
A mushroom coral! Rose Atoll, 680 m


Probably the BIG, weird star of this leg was this BIZARRE blobby tree shaped thing! Turns out its a bizarre sea anemone in the family Aliciidae! Its tentacles had been withdrawn...
It turns out we saw one of these during the Marianas expedition LAST year!  Which makes the one above a likely DIFFERENT species from the other one we saw which had yellow buttons rather than white ones..

Dr. Dave Pawson at the National Museum of Natural History was apparently stung by one of these (only 6 inches long) and reported that each of these buttons are batteries of STINGING cells which can cause painful stings that last for several hours!! (click here

MOLLUSKS! 
Unsurprisingly, some of the most exciting observations on this last cruise were MOLLUSKS! We don't normally see a lot of snails or clams on these cruises..but we made up for it on this dive! 

Neopilina, MONOPLACOPHORAN! 
Few animals that I know of have what might be considered "holy grail" status. THIS is one of them..

In this case, the mysterious mollusk known as Neopilina! This mysterious mollusk has previously been collected from abyssal and ultrabyssal depths between 4000 and 6000 meters. From both the Atlantic and the Pacific. 

These are rarely collected and in the past were perceived as being VERY important to evolutionary or other ecological studies.  Basically these animals were regarded as ancient AND ancestral mollusks-the "Ur mollusk" if you will. They inspired a LOT of questions about what they were related to and how other mollusks were related to one another.. 

But I think this might be the FIRST time an in situ (in place and ALIVE) observation has been made! I admit that this tiny brown limpet thing does not have the same... presence as say some giant octopus  or squid, but once you know all the history behind it.. well, I say this with no irony-seeing it alive in its habitat was HISTORIC!!


Octopus!  So, of course we are always fond of cephalopods when they turn up! This white translucent octopus species was observed at least twice on the dive at relatively "shallow" depths between 380 and 400 m. This first shot was from Tau seamount.

Note that the webs of skin between the arms were translucent! 
This one was seen at Rose Atoll at about 393 m and it was investigating a series of little holes and caves.. presumably looking for food..



ECHINODERMS!! So, where MY group is concerned I'm always a little biased and have more imagery than of other groups (not as many corals for example). And because I work on starfishes-there's enough pics that I will get to those in another post!

but for now, here's some striking "spiny-skinned" friends that I saw...


This funny beast which I think was in the Deimatidae? Note that as with many deep-sea sea cucumbers, the body wall was translucent and we can see the sediment eaten by the animal THROUGH the body wall! 
The bizarre semi-swimming sea cucumber Psychropotes I blogged about this genus of sea cucumber and the number of species there might in the world oceans! 
This sea cucumber (Paelopatides?) in free swim glide! Moki Seamount about 2083 m WHEEEE!

This interesting fold over backwards behavior of a sea cucumber at Utu Seamount

A sea urchin the family Pedinidae I think? Lovely greenish coloration!
A reddish.. echinothuriid urchin? Aka a "pancake" or "tam o shanter" urchin. I've written about these before  here.  We saw a few different species of these kinds of urchins. But they are difficult to ID from pictures..

MIXED TAXON CRAB + COMBINATION!!
There were at least two interesting cases where we saw crustaceans "team up" with another animal that one does not normally associate.....

1. Decorator crab + cidaroid urchin! This was an odd one. The ROV was observing this cidaroid urchin..and as it changed angles.. it noticed this majiid type "decorator" crab hanging on with its rear legs. We've seen other crabs hanging onto fire urchins in tropical shallow-water habitats as protection-but not seen something like this. Unclear if it is incidental or something that happens regularly...

2. Zoanthid "anemone" PLUS hermit crab! A relationship that has been seen before but no less weird whenever we see it. Basically a sea anemone-like animal called a zoanthid rides and replaces the shell that this hermit crab would normally be wearing..

The crab benefits from the protection and the zoanthid gets driven around by the crab for dispersion, food, etc.. Interesting commensalism!

Here's a nice one seen back in 2015 by Diva Amon!